Document the Discord status text

docs/customization.md

@@ -36,14 +36,21 @@ Discord settings (Settings > Discord, saved to `config.json`):
 
 - elapsed, remaining, both or no timestamps (`discord.timestamps`);
 - idle behaviour (`discord.idleBehavior`);
+- the status text next to your name (`discord.name`) and which line Discord shows there (`discord.statusDisplayType`: `name`, `state` or `details`);
 - album art lookup (`discord.artworkLookup`, off by default).
 
-Wording templates, buttons, asset keys and the update interval can't be changed yet. Values for them in `config.json` are ignored, and a settings save removes them.
+Wording templates for the other lines, buttons, asset keys and the update interval can't be changed yet. Values for them in `config.json` are ignored, and a settings save removes them.
 
 TV episodes with a known series show the series and episode code, for example "Lost" and "S04E05 · The Constant".
 
 Discord Rich Presence runs locally and communicates with the user's Discord IPC socket. Analytics, when explicitly enabled, sends only one anonymous installation ping.
 
+## Status text
+
+Discord shows `<artist> on <service>` by default, for example "fakemink on Spotify". Films and episodes keep Discord's own app name unless you set a status text. Change it in Settings > Discord > Status text, or set `discord.name` in `config.json`. Leave it empty for the default.
+
+Write fields in braces: `{artist}`, `{title}`, `{subtitle}`, `{album}`, `{year}`, `{series}`, `{season}`, `{episode}`, `{episodeCode}`, `{service}` (Spotify, Navidrome, Plex and so on), `{provider}`, `{mediaType}`, `{state}`, `{stateLabel}`, `{position}`, `{duration}` and `{progressPercent}`. Other text is kept as typed. Write `{{` or `}}` for a literal brace. A field that is not in this list is rejected when you save. The text can be 128 characters at most. With hidden titles on, `{artist}` is blank.
+
 ## Privacy
 
 Privacy is applied before formatting. Removed data cannot be restored by card or Discord visibility settings.